This invention is used for high pressure hot water chemical washers in which acids or other chemicals are injected at the nozzles. The high pressure hot water chemical washers are used for many purposes.
The apparatus is used with plain, inexpensive muriatic acid for most masonry cleaning jobs. If special chemicals are specified, the apparatus can use the special chemicals. The apparatus cleans mortar from rough surface brick, Type S mortar, Portland cement spatter, Sarabond, efflorescence, vanadium or manganese. Smoke damage and tar are removed by the present apparatus without leaving stains. The apparatus cleans atmospheric deposits such as dirt, black carbon, rust, green mold and other deposits from masonry, stone or plaster surfaces.
The device is simplified and sturdy.
Underlying technology is described and claimed in U.S. Pat. Nos. 3,997,114, 4,046,321 and 4,287,912 and U.S. Pat. No. Des. 239,048.
A need has existed for high pressure hot water acid wash systems in which water temperature and pressures are carefully controlled.
The present invention describes and claims improvements which simplify the apparatus and improve operation.
SUMMARY OF THE INVENTION
The invention provides an improved simplified high pressure hot water chemical washer apparatus and method.
The present invention controls water temperature by anticipating needs for heating and for stopping heating. The present invention controls water pressure maximums throughout the system immediately at locations where pressure increases are or may be generated. By so doing, the present invention assures controlled system pressures on system components and longevity of the washer with increased operations at maximum temperatures and pressures.
In using the method, a high pressure hot water acid washer is towed to a site on a trailer. A chemical tank and gasoline and diesel fuel tanks are filled. A water supply hose is connected to a water tank. A power cord is connected to a power source. A float valve controls the filling and maintaining of the water level in the water tank. Water flows from the water tank through a filter to a water pump. The water pump and a compressor are driven with a gasoline engine. Overpressure is released at the heat exchanger, enabling the pump to operate at maximum pressures during periods of maximum water flow without preaccounting for expected pressure spikes, on valve shutoff, for example. Pressurized water flows through a flow switch to a heat exchanger. The flow switch, upon sensing flow, completes a power circuit to operate a fuel pump with an electric motor, anticipating heating demands and stopping heating when flow is stopped, even for a short time, and permitting the heat exchanger to operate at high maximum temperatures. Fuel is pumped from the fuel tank and is vaporized and sprayed into the heat exchanger. An ignition coil ignites the fuel. The power circuit is interrupted upon sensing a high temperature in a pressurized water delivery line from the heat exchanger. Pressure of pressurized hot water in the delivery line is limited by a hot water pressure relief valve, enabling the operations of the system to be at maximum high pressures without undue stress of components. Pressurized hot water flows out through a high pressure hot water hose and nozzle. The chemical tank is pressurized with air from the compressor, which flows through a pressure relief valve and a unidirectional check valve. Chemical flows from the chemical tank under the influence of air pressure through a chemical line. Rate of flow of chemical is controlled with a needle valve. Opening the chemical line with a ball valve releases chemical to the fast hot water stream from the nozzle.
A high pressure hot water acid injection washer apparatus has a gasoline engine. A water pump and a compressor are driven by the engine. A water intake line is connected to the pump, and a Y-type water filter is mounted in the intake line. A water supply is connected to the intake line for supplying water through the filter to the pump. A drain connected to the pump drains water from the pump. A pressurized water outlet is connected to the pump. A bypass is connected to the outlet and is connected to the water supply for returning water from the outlet of the pump to the water supply upon lack of flow. A pressurized water flow line is connected to the outlet. A flow switch is mounted in the pressurized water flow line for sensing flow of water through the flow line. A heat exchanger is connected to the pressurized flow line for receiving water flowing through the pressurized water flow line and the flow switch.
A fuel pump and a burner are connected to a fuel tank and are operated by a motor connected to the flow switch for operating the pump and burner when the flow switch senses flow of water to the heat exchanger. A high pressure hot water delivery line is connected to the heat exchanger outlet port. A temperature sensor control is connected to the hot water delivery line and is connected to the pump motor and burner, for permitting operation of the pump and burner until a predetermined high temperature is sensed from the outlet port. A high pressure hot water delivery hose and a high pressure hot water nozzle are connected to a hot water pressure relief valve at an end of the delivery line for releasing excess pressure in the hot water line before reaching the delivery hose.
The filter supplies clean particle-free water to the pump. The entire construction may be built without excess materials. A bypass opens to release pump output pressures to the water tank, when flow through the heat exchanger and nozzle is stopped. A reducing-type pressure relief valve relieves overpressures, shocks and hammers which might be created by opening and closing valves, for example. The flow switch permits operation of the fuel pump and burner only when water is flowing from the pump to the heat exchanger. The aquastat prevents the excess heating of the water, which might result in the production of too hot pressurized water or water that might flash to steam upon being released.
The water supply includes a water tank having an inlet connection for a hose and having a float valve controlling the inlet. The water tank supplies water from a water source to the water filter and the water pump.
The compressor is connected to an air line, and the air line is connected to a chemical tank for pressurizing the chemical tank. A valve in the air line prevents air pressure and acid fumes from flowing from the acid tank back to the compressor. A chemical line is connected to the chemical tank for delivering chemical under influence of the air pressure. A needle valve is mounted in the chemical line for controlling flow of chemical through the chemical line. A ball valve is connected to the needle valve for opening and closing the chemical line. A chemical injector connected to the ball valve releases chemical into a hot water stream from a nozzle.
A preferred portable high pressure acid wash apparatus, has a trailer frame. An axle and wheels are mounted on the frame, and a tow hitch is connected to the frame for transporting the frame. A stand is connected to the frame near the tow hitch for supporting the frame when stationary.
A power circuit on the frame receives electrical power from a cord and a plug. A motor is coupled to the power circuit and connected to the fuel pump for driving the fuel pump and vaporizing and spraying fuel into the heat exchanger. An ignition coil is connected to the power circuit for igniting vaporized fuel in the heat exchanger. The flow switch is connected to the power circuit and to the motor and ignition coil and connected to the water pressure line for permitting operation of the motor and ignition coil upon sensing flow in the water pressure line.
A high temperature control is connected to the power circuit and to the pressurized hot water delivery line for permitting completion of the power circuit and operation of the pump and ignition coil upon sensing temperature below a predetermined level in the pressurized hot water delivery line.
These and further and other objects and features of the invention are apparent in the disclosure, which includes the above and ongoing written specification, with the claims and the drawings.